Retrospective Cohort Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Jul 15, 2020; 12(7): 732-740
Published online Jul 15, 2020. doi: 10.4251/wjgo.v12.i7.732
Prognostic role of ultrasonography staging in patients with anal cancer
Paola De Nardi, Giaime G Arru, Giovanni Guarneri, Iliyan Vlasakov, Luca Massimino
Paola De Nardi, Giaime G Arru, Giovanni Guarneri, Gastrointestinal Surgery, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy
Iliyan Vlasakov, Vita-Salute University San Raffaele, Milan 20132, Italy
Luca Massimino, Laboratory of Immunopathology in Gastroenterology, Humanitas University, Pieve Emanuele, Milan 20132, Italy
Author contributions: De Nardi P designed the study, drafted the manuscript, participated in the acquisition, analysis, and interpretation of the data; Arru G, Guarneri G and Vlasakov I participated in the acquisition, analysis and interpretation of the data, revised the article critically for important intellectual content, and approved the final version; Massimino L participated in the analysis and interpretation of the data, revised the article critically for important intellectual content, provided the statistical analysis and approved the final version.
Institutional review board statement: No Institute review board approval is needed for retrospective observational studies.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to enrollment.
Conflict-of-interest statement: There are no conflicts of interest to report.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Paola De Nardi, MD, Doctor, Gastrointestinal Surgery, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, Milan 20132, Italy. denardi.paola@hsr.it
Received: December 30, 2019
Peer-review started: December 30, 2019
First decision: April 2, 2020
Revised: May 28, 2020
Accepted: June 14, 2020
Article in press: June 14, 2020
Published online: July 15, 2020
Abstract
BACKGROUND

Carcinomas of the anal canal are staged according to the size and extent of the disease; however, we propose including a novel ultrasound (US) staging system, based on depth of tumor invasion. In this study the clinical American Joint Committee on Cancer (AJCC) staging guidelines and the US classificationss in patients with anal cancer were compared.

AIM

To evaluate the prognostic role of the US staging system in patients with anal cancer.

METHODS

The data of 48 patients with anal canal squamous cells carcinoma, observed at our University Hospital between 2007 and 2017, who underwent pre-treatment assessment with pelvic magnetic resonance imaging (MRI), total body computed tomography (CT) scan and endoanal US were retrospectively reviewed. Anal canal tumors were clinically staged according to AJCC, determined by MRI by measurement of the longest tumor diameter, and CT scan. Endoanal US was performed with a high multi-frequency (9-16 MHz), 360° rotational mechanical probe; US classification was based on depth of tumor penetration through the anal wall, according to Giovannini’s study. All patients were treated with definitive radiation combined with 5-fluorouracile and Mitomycin-C. After treatment patients were followed-up regularly.

RESULTS

At baseline there were 30 and 32 T1-2, 18 and 16 T3-4, 31 and 19 N+ patients classified according to the clinical AJCC and US staging system respectively. After a mean follow-up of 98 months, 38 patients (79.1%) are alive and 28 (58.3%) are disease free. During follow up 20 patients (41.6%) experienced recurrences. After univariate analysis, American Society of Anesthesiologists (ASA) score (P = 0.00000001) and US staging (P = 0.009) were significantly related to disease-free survival (DFS). When overall survival and DFS functions were compared, a statistically significant difference was observed for DFS survival when the US staging was applied with respect to the clinical AJCC staging. By combining the 2 significant prognostic variables, namely the US staging with the ASA score, four risks groups with different prognoses were identified.

CONCLUSION

Our findings suggest that US staging may be superior to traditional clinical staging, since it is significantly associated with DFS in anal cancer patients.

Keywords: Anal cancer, Ultrasonography staging, American Joint Committee on Cancer staging, Prognosis, Disease-free survival, Staging

Core tip: In this paper the prognostic role of the ultrasound (US) staging system based on tumor penetration through the anal canal wall was examined and compared to the clinical American Joint Committee on Cancer staging system, in anal cancer patients. The results showed that US classification was significantly associated with disease-free survival. This classification could be introduced as one of the predictive clinical parameters to better stratify patients into risk categories.